Functionalized cyclosilazanes as precursors for high growth rate silicon-containing films

ABSTRACT

Described herein are functionalized cyclosilazane precursor compounds and compositions and methods comprising same to deposit a silicon-containing film such as, without limitation, silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, silicon oxycarbonitride, or carbon-doped silicon oxide via a thermal atomic layer deposition (ALD) or plasma enhanced atomic layer deposition (PEALD) process, or a combination thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claim priority under 35 U.S.C. § 119(e) to U.S.provisional patent application No. 62/510,506, filed on May 24, 2017,the entirety of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Described herein are functionalized cyclosilazane precursor compoundsand compositions and methods comprising same to deposit asilicon-containing film such as, without limitation, silicon oxide,silicon nitride, silicon oxynitride, silicon carbonitride, siliconoxycarbonitride, or carbon-doped silicon oxide via a thermal atomiclayer deposition (ALD) or plasma enhanced atomic layer deposition(PEALD) process, or a combination thereof. More specifically, describedherein is a composition and method for formation of a stoichiometric ora non-stoichiometric silicon-containing film or material at one or moredeposition temperatures of about 600° C. or less including, for example,from about 25° C. to about 300° C.

Atomic Layer Deposition (ALD) and Plasma Enhanced Atomic LayerDeposition (PEALD) are processes used to deposit, for example, siliconoxide conformal films at low temperature (<500° C.). In both ALD andPEALD processes, the precursor and reactive gas (such as oxygen orozone) are separately pulsed in certain number of cycles to form amonolayer of silicon oxide at each cycle. However, silicon oxidedeposited at low temperatures using these processes may contain levelsof impurities such as, without limitation, nitrogen (N) which may bedetrimental in certain semiconductor applications. To remedy this, onepossible solution is to increase the deposition temperature to 500° C.or greater. However, at these higher temperatures, conventionalprecursors employed by semi-conductor industries tend to self-react,thermally decompose, and deposit in a chemical vapor deposition (CVD)mode rather than an ALD mode. The CVD mode deposition has reducedconformality compared to ALD deposition, especially for high aspectratio structures which are needed in many semiconductor applications. Inaddition, the CVD mode deposition has less control of film or materialthickness than the ALD mode deposition.

The reference article entitled “Some New Alkylaminosilanes,” Abel, E. W.et al., J. Chem. Soc., (1961), Vol. 26, pp. 1528-1530 describes thepreparation of various aminosilane compounds such as Me₃SiNHBu-iso,Me₃SiNHBu-sec, Me₃SiN(Pr-iso)₂, and Me₃SiN(Bu-sec)₂ wherein Me=methyl,Bu-sec=sec-butyl, and Pr-iso=isopropyl from the direct interaction oftrimethylchlorosilane (Me₃SiCl) and the appropriate amine.

The reference article entitled “SiO₂ Atomic Layer Deposition UsingTris(dimethylamino)silane and Hydrogen Peroxide Studied by in SituTransmission FTIR Spectroscopy,” Burton, B. B., et al., The Journal ofPhysical Chemistry (2009), Vol. 113, pp. 8249-57 describes the atomiclayer deposition (ALD) of silicon dioxide (SiO₂) using a variety ofsilicon precursors with H₂O₂ as the oxidant. The silicon precursors were(N,N-dimethylamino)trimethylsilane) (CH₃)₃SiN(CH₃)₂,vinyltrimethoxysilane CH₂CHSi(OCH₃)₃, trivinylmethoxysilane(CH₂CH)₃SiOCH₃, tetrakis(dimethylamino)silane Si(N(CH₃)₂)₄, andtris(dimethylamino)silane (TDMAS) SiH(N(CH₃)₂)₃. TDMAS was determined tobe the most effective of these precursors. However, additional studiesdetermined that SiH* surface species from TDMAS were difficult to removeusing only H₂O. Subsequent studies utilized TDMAS and H₂O₂ as theoxidant and explored SiO₂ ALD in the temperature range of 150-550° C.The exposures required for the TDMAS and H₂O₂ surface reactions to reachcompletion and were monitored using in situ FTIR spectroscopy. The FTIRvibrational spectra following the TDMAS exposures showed a loss ofabsorbance for O—H stretching vibrations and a gain of absorbance forC-Hx and Si—H stretching vibrations. The FTIR vibrational spectrafollowing the H₂O₂ exposures displayed a loss of absorbance for C-Hx andSi—H stretching vibrations and an increase of absorbance for the O—Hstretching vibrations. The SiH* surface species were completely removedonly at temperatures >450° C. The bulk vibrational modes of SiO₂ wereobserved between 1000-1250 cm⁻¹ and grew progressively with number ofTDMAS and H₂O₂ reaction cycles. Transmission electron microscopy (TEM)was performed after 50 TDMAS and H₂O₂ reaction cycles on ZrO₂nanoparticles at temperatures between 150-550° C. The film thicknessdetermined by TEM at each temperature was used to obtain the SiO₂ ALDgrowth rate. The growth per cycle varied from 0.8 Å/cycle at 150° C. to1.8 Å/cycle at 550° C. and was correlated with the removal of the SiH*surface species. SiO₂ ALD using TDMAS and H₂O₂ should be valuable forSiO₂ ALD at temperatures >450° C.

JP 2010275602 and JP 2010225663 disclose the use of a raw material toform a Si containing thin film such as, silicon oxide, by a chemicalvapor deposition (CVD) process at a temperature range of from 300-500°C. The raw material is an organic silicon compound, represented byformula: (a) HSi(CH₃)(R¹)(NR²R³), wherein, R¹ represents NR⁴R⁵ or a1C-5C alkyl group; R² and R⁴ each represent a 1C-5C alkyl group orhydrogen atom; and R³ and R⁵ each represent a C₁-C₅ alkyl group); or (b)HSiCl(NR¹R²)(NR³R⁴), wherein R¹ and R³ independently represent an alkylgroup having 1 to 4 carbon atoms, or a hydrogen atom; and R² and R⁴independently represent an alkyl group having 1 to 4 carbon atoms. Theorganic silicon compounds contained H—Si bonds.

U.S. Pat. No. 5,424,095 describes a method to reduce the rate of cokeformation during the industrial pyrolysis of hydrocarbons, the interiorsurface of a reactor is coated with a uniform layer of a ceramicmaterial, the layer being deposited by thermal decomposition of anon-alkoxylated organosilicon precursor in the vapor phase, in a steamcontaining gas atmosphere in order to form oxide ceramics.

U.S. 2012/0291321 describes a PECVD process for forming a high-qualitySi carbonitride barrier dielectric film between a dielectric film and ametal interconnect of an integrated circuit substrate, comprising thesteps of: providing an integrated circuit substrate having a dielectricfilm or a metal interconnect; contacting the substrate with a barrierdielectric film precursor comprising: R_(x)R_(y)(NRR′)_(z)Si wherein R,R′, R and R′ are each individually selected from H, linear or branchedsaturated or unsaturated alkyl, or aromatic group; wherein x+y+z=4; z=1to 3; but R, R′ cannot both be H; and where z=1 or 2 then each of x andy are at least 1; forming the Si carbonitride barrier dielectric filmwith C/Si ratio>0.8 and a N/Si ratio >0.2 on the integrated circuitsubstrate.

U.S. 2013/0295779 A describes an atomic layer deposition (ALD) processfor forming a silicon oxide film at a deposition temperature >500° C.using silicon precursors having the following formula:R¹R² _(m)Si(NR³R⁴)_(n)X_(p)  I.wherein R¹, R², and R³ are each independently selected from hydrogen, alinear or branched C₁ to C₁₀ alkyl group, and a C₆ to C₁₀ aryl group; R⁴is selected from, a linear or branched C₁ to C₁₀ alkyl group, and a C₆to C₁₀ aryl group, a C₃ to C₁₀ alkylsilyl group; wherein R³ and R⁴ arelinked to form a cyclic ring structure or R³ and R⁴ are not linked toform a cyclic ring structure; X is a halide selected from the groupconsisting of Cl, Br and I; m is 0 to 3; n is 0 to 2; and p is 0 to 2and m+n+p=3; andR¹R² _(m)Si(OR³)_(n)(OR⁴)_(q)X_(p)  II.wherein R¹ and R² are each independently selected from hydrogen, alinear or branched C₁ to C₁₀ alkyl group, and a C₆ to C₁₀ aryl group; R³and R⁴ are each independently selected from a linear or branched C₁ toC₁₀ alkyl group, and a C₆ to C₁₀ aryl group; wherein R³ and R⁴ arelinked to form a cyclic ring structure or R³ and R⁴ are not linked toform a cyclic ring structure; X is a halide atom selected from the groupconsisting of Cl, Br and I; m is 0 to 3; n is 0 to 2; q is 0 to 2 and pis 0 to 2 and m+n+q+p=3.

U.S. Pat. No. 7,084,076 discloses a halogenated siloxane such ashexachlorodisiloxane (HCDSO) that is used in conjunction with pyridineas a catalyst for ALD deposition below 500° C. to form silicon dioxide.

U.S. Pat. No. 6,992,019 discloses a method for catalyst-assisted atomiclayer deposition (ALD) to form a silicon dioxide layer having superiorproperties on a semiconductor substrate by using a first reactantcomponent consisting of a silicon compound having at least two siliconatoms, or using a tertiary aliphatic amine as the catalyst component, orboth in combination, together with related purging methods andsequencing. The precursor used is hexachlorodisilane. The depositiontemperature is between 25-150° C.

WO 2015/0105337 discloses novel trisilyl amine derivatives and a methodfor formation of silicon containing thin films, wherein the trisilylamine derivatives are having thermal stability, high volatility, andhigh reactivity and being present in a liquid state at room temperatureand under pressure where handling is possible, may form a high puritysilicon containing thin film having excellent physical and electricproperties by various deposition methods.

WO 2015/0190749 discloses novel amino-silyl amine compounds,(Me₂NSiR³R⁴)N(SiHR¹R²)₂ (R¹—R⁴═C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl,C₃₋₇ cycloalkyl, C₆₋₁₂ aryl, etc.), and a method of a dielectric filmcontaining Si—N bond. Since the amino-silyl amine compd. according tothe present invention, which is a thermally stable and highly volatilecompound, may be treated at room temperature and used as a liquid statecompd. at room temp. and pressure, the present invention provides amethod of a high purity dielectric film containing a Si—N bond even at alow temperature and plasma condition by using atomic layer deposition(PEALD).

U.S. Pat. No. 9,245,740 provides novel amino-silyl amine compounds, amethod for preparing the same, and a silicon-containing thin-film usingthe same, wherein the amino-silyl amine compound has thermal stabilityand high volatility and is maintained in a liquid state at roomtemperature and under a pressure where handling is easy to thereby forma silicon-containing thin-film having high purity and excellent physicaland electric properties by various deposition methods.

U.S. 2015/0376211A discloses mono-substituted TSA precursorSi-containing film forming compositions are disclosed. The precursorshave the formula: (SiH₃)₂N—SiH₂—X, wherein X is selected from a halogenatom; an isocyanato group; an amino group; an N-containing C₄-C₁₀saturated or unsaturated heterocycle; or an alkoxy group. Methods forforming the Si-containing film using the disclosed mono-substituted TSAprecursor are also disclosed.

U.S. Pat. No. 3,444,127 describes the synthesis of polymericarene-linked silicones by reacting functionalized1,3-dioxa-5-aza-trisilacyclohexanes with arene-linked silanols andheating the mixture to as high as 180° C.

U.S. Pat. No. 5,413,813 and U.S. Pat. No. 5,424,095 describe the use ofdifferent hexamethylcyclotrisilazanes and other silazanes to coat themetal or metal oxide surfaces inside a reactor chamber with a ceramicmaterial at high temperatures in order to prevent coking in subsequentreactor processes involving the pyrolysis of hydrocarbons.

US2015126045A1 describes the deposition of silicon nitride layer on asubstrate by using a remote plasma and hexamentylcyclotrisilazane orother aminosilanes in a plasma-enhanced CVD process at temperatures lessthan 300° C.

US2016379819A1 describes the use of a UV-assisted photochemical vaporcomprising different silazanes including hexamethylcyclotrisilazane forthe purpose of pore-sealing pourous low-dielectric films.

US20130330482A1 describes the deposition of carbon-doped silicon nitridefilms via plasma-enhanced CVD process using vinyl-substitutedcyclotrisilazanes or other silazanes as precursors.

US20160032452A1 describes an ALD process in which at least one metalorganic source molecule is reacted with hydrogen radicals and anothersource gas to produce metal-containing films.

The previously identified patents, patent applications and publicationsare hereby incorporated by reference.

There is a need in this art for a process for forming uniform andconformal silicon-containing films such as silicon oxide having at leastone or more of the following attributes: a density of about 2.1 g/cc orgreater, a growth rate of 2.0 Å/cycle or greater, low chemical impurity,and/or high conformality in a thermal atomic layer deposition, a plasmaenhanced atomic layer deposition (ALD) process or a plasma enhancedALD-like process using cheaper, reactive, and more stable siliconprecursor compounds.

BRIEF SUMMARY OF THE INVENTION

The instant invention solves the need in this art by providingcompositions and processes for the deposition of a stoichiometric ornonstoichiometric silicon-containing material or film, such as withoutlimitation, a silicon oxide, a carbon doped silicon oxide, a siliconoxynitride film, silicon nitride, a carbon doped silicon nitride, or acarbon doped silicon oxynitride film at relatively low temperatures,e.g., at one or more temperatures of 600° C. or lower, in the followingdeposition process: a plasma enhanced ALD, plasma enhanced cyclicchemical vapor deposition (PECCVD), a flowable chemical vapor deposition(FCVD), a plasma enhanced flowable chemical vapor deposition (PEFCVD), aplasma enhanced ALD-like process, or an ALD process withoxygen-containing reactant source, a nitrogen-containing reactantsource, or a combination thereof.

In one aspect, there is provided a silicon precursor compound accordingto one of Formulae A, B, C, D, or E:

wherein R¹⁻³ are each independently selected from the group consistingof hydrogen, methyl, and an organoamino group (NR′R″), wherein R′ and R″are each independently selected from the group consisting of hydrogen, aC₁₋₁₀ linear alkyl group, a C₃₋₁₀ branched alkyl group, a C₃₋₁₀ cyclicalkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀ aryl group, and a C₄₋₁₀heterocyclic group, with the proviso that R′ and R″ cannot both behydrogen; R⁴ and R⁵ are each independently selected from the groupconsisting of hydrogen, a C₁₋₁₀ linear alkyl group, a C₃₋₁₀ branchedalkyl group, a C₃₋₁₀ cyclic alkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀aryl group, and a C₄₋₁₀ heterocyclic group; R⁶⁻⁸ are each independentlyselected from the group consisting of hydrogen, methyl, an organoaminogroup (NR′R″) as defined above, a C₃₋₁₀ branched alkyl group, a C₃₋₁₀cyclic alkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀ aryl group, and aC₄₋₁₀ heterocyclic group, with the proviso that R′ and R″ cannot both behydrogen, wherein two or more of substituents R¹⁻⁸, R′, and R″ may belinked to form a substituted or unsubstituted, saturated or unsaturated,cyclic group, and wherein at least one of R⁶⁻⁸ must be hydrogen, and atleast two of R⁶⁻⁸ must not be methyl.

In addition to conventional methods of synthesizing silazane moleculessuch as the reaction of chlorosilanes with amines or metal amides toform Si—N bonds, compounds having Formulae A to E can be synthesized,for example, by catalytic dehydrocoupling between at least one N—H bondof an organoamine, linear silazane or cyclosilazane moiety with ahydridosilane having at least one Si—H group (e.g. Equations 1-5).

Exemplary dehydrocoupling catalysts include, but are not limited to,tris(pentafluorophenyl)borane, BR₃ (wherein R is selected from a linear,branched, or cyclic C₁ to C₁₀ alkyl groupgroup, a C₅ to C₁₀ aryl group,or a C₁ to C₁₀ alkoxy group),1,3-disopropyl-4,5-dimethylimidazol-2-ylidene, 2,2′-bipyridyl,phenanthroline, Mg[N(SiMe₃)₂]₂,[tris(4,4-dimethyl-2-oxazolinyl)phenylborate]MgMe,[tris(4,4-dimethyl-2-oxazolinyl)phenylborate]MgH, trimethylaluminium,triethylaluminum, aluminum chloride, Ca[N(SiMe₃)₂]₂, dibenzylcalcium,{CH—[CMeNC₆H₃-2,6-^(i)Pr₂]₂}CaH, triruthenium dodecacarbonyl,{CH—[CMeNC₆H₃-2,6-^(i)Pr₂]₂}Ca[N(SiMe₃)₂],bis(cyclopentadienyl)dialkylltitanium(IV),bis(cylopentadienyl)titanium(IV)difluoride,bis(cylopentadienyl)titanium(IV)dichloride,bis(cylopentadienyl)titanium(IV)dihydride, TiMe₂(dmpe)₂[dmpe=1,2-bis(dimethylphosphino)ethane], (C₅H₅)₂Ti(OAr)₂ [Ar=(2,6-(iPr)2C₆H₃)], (C₅H₅)₂Ti(SiHRR′)PMe₃ [wherein R, R′ are each independentlyselected from a hydrogen atom (H), a methyl group (Me), and a phenyl(Ph) group], bis(benzene) chromium(0), chromium hexacarbonyl,dimanganese decacarbonyl, [Mn(CO)₄Br]₂, iron pentacarbonyl,(C₅H₅)Fe(CO)₂Me, dicobalt octacarbonyl, nickel(II) acetate, nickel(II)chloride, [(dippe)Ni(μ-H)]2 [dippe=1,2-bis(diisopropylphosphino)ethane],(R-indenyl)Ni(PR′₃) Me [wherein R is selected from 1-i-Pr, 1-SiMe₃, and1,3-(SiMe₃)₂; wherein R′ is selected from a methyl (Me) group andaphenyl (Ph) group], [{Ni(η-CH₂:CHSiMe₂)₂O}₂{μ-(η-CH₂:CHSiMe₂)₂O}],nickel(II) acetylacetonate, ni(cyclooctadiene)₂, copper(II) fluoride,copper(I) chloride, copper(II) chloride, copper(I) bromide, copper(II)bromide, copper(I) iodide, copper(I) acetate, Cu(PPh₃)₃Cl, zincchloride, [tris(4,4-dimethyl-2-oxazolinyl)phenylborate]ZnH,Sr[N(SiMe₃)₂]₂, Bis(cyclopentadienyl)dialkyllzirconium(IV),Bis(cylopentadienyl)zirconium(IV)difluoride,Bis(cylopentadienyl)zirconium(IV)dichloride,bis(cylopentadienyl)zirconium(IV)dihydride,[(Et₃P)Ru(2,6-dimesitylthiophenolate)][B[3,5-(CF₃)₂C₆H₃]₄],(C₅Me₅)Ru(R₃P)_(x)(NCMe)_(3-x)]⁺ (wherein R is selected from a linear,branched, or cyclic C₁ to C₁₀ alkyl group and a C₅ to C₁₀ aryl group;x=0, 1, 2, 3), tris(triphenylphosphine) rhodium(I)carbonyl hydride,di-μ-chloro-tetracarbonyldirhodium(I), tris(triphenylphosphine)rhodium(I) chloride (Wilkinson's Catalyst), hexarhodiumhexadecacarbonyl, tris(triphenylphosphine)rhodium(I) carbonyl hydride,bis(triphenylphosphine)rhodium(I) carbonyl chloride,[RhCl(cyclooctadiene)]2, tris(dibenzylideneacetone)dipalladium(0),tetrakis(triphenylphosphine)palladium(0), palladium(11) acetate,palladium(11) chloride, palladium(II) iodide, cesium carbonate,(C₅H₅)₂SmH, (C₅Me₅)₂SmH, (NHC)Yb(N(SiMe₃)₂)₂[NHC=1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene)], tungstenhexacarbonyl, dirhenium decacarbonyl, triosmium dodecacarbonyl,tetrairidium dodecacarbonyl, (acetylacetonato) dicarbonyliridium(I),(POCOP)IrHCl [(POCOP)=2,6-(R₂PO)₂C₆H₃, (R is selected from isopropyl(iPr), normal butyl (nBu), and methyl (Me)], Ir(Me)₂(C₅Me₅)L [wherein Lis selected from PMe₃ and PPh₃], [Ir(cyclooctadiene)OMe]2,platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane (Karstedt'sCatalyst), H₂PtCl₆·nH₂O (chloroplatinic acid),bis(tri-tert-butylphosphine)platinum(0), PtO₂, and Pt(cyclooctadiene)₂.

Catalysts can also be the present affixed to a support. The support is asolid with a high surface area. Typical support materials include butare not limited to: alumina, MgO, zeolites, carbon, Monolith cordierite,diatomaceous earth, silica gel, silica/alumina, ZrO and TiO₂. Preferredsupports are carbon (for examples, platinum on carbon, palladium oncarbon, rhodium on carbon, ruthenium on carbon) alumina, silica and MgO.Metal loading of the catalyst ranges between about 0.01 weight percentto about 50 weight percent. A preferred range is about 0.5 weightpercent to about 20 weight percent. A more preferred range is about 0.5weight percent to about 10 weight percent. Catalysts requiringactivation may be activated by a number of known methods. Heating thecatalyst under vacuum is a preferred method. The catalyst may beactivated before addition to the reaction vessel or in the reactionvessel prior adding the reactants. The catalyst may contain a promoter.Promoters are substances which themselves are not catalysts, but whenmixed in small quantities with the active catalysts increase theirefficiency (activity and/or selectivity). Promoters are usually metalssuch as Mn, Ce, Mo, Li, Re, Ga, Cu, Ru, Pd, Rh, Ir, Fe, Ni, Pt, Cr, Cuand Au and/or their oxides. They can be added separately to the reactorvessel or they can be part of the catalysts themselves. For example,Ru/Mn/C (ruthenium on carbon promoted by manganese) or Pt/CeO₂/Ir/SiO₂(Platinum on silica promoted by ceria and iridium). Some promoters canact as catalyst by themselves but their use in combination with the maincatalyst can improve the main catalyst's activity. A catalyst may act asa promoter for other catalysts. In this context, the catalyst can becalled a bimetallic (or polymetallic) catalyst. For example, Ru/Rh/C canbe called either ruthenium and rhodium on carbon bimetallic catalyst orruthenium on carbon promoted by rhodium. An active catalyst is amaterial that acts as a catalyst in a specific chemical reaction.

In another embodiment, there is provided a method for depositing asilicon-containing film onto a substrate which comprises the steps of:providing a substrate in a reactor; introducing into the reactor atleast one silicon precursor compound comprising at least one siliconprecursor compound according to one of Formulae A, B, C, D, or E:

wherein R¹⁻³ are each independently selected from the group consistingof hydrogen, methyl, and an organoamino group (NR′R″), wherein R′ and R″are each independently selected from the group consisting of hydrogen, aC₁₋₁₀ linear alkyl group, a C₃₋₁₀ branched alkyl group, a C₃₋₁₀ cyclicalkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀ aryl group, and a C₄₋₁₀heterocyclic group, with the proviso that R′ and R″ cannot both behydrogen; R⁴ and R⁵ are each independently selected from the groupconsisting of hydrogen, a C₁₋₁₀ linear alkyl group, a C₃₋₁₀ branchedalkyl group, a C₃₋₁₀ cyclic alkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀aryl group, and a C₄₋₁₀ heterocyclic group; R⁶⁻⁸ are each independentlyselected from the group consisting of hydrogen, methyl, an organoaminogroup (NR′R″) as defined above, a C₃₋₁₀ branched alkyl group, a C₃₋₁₀cyclic alkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀ aryl group, and aC₄₋₁₀ heterocyclic group, with the proviso that R′ and R″ cannot both behydrogen, wherein two or more of substituents R¹⁻⁵, R′, and R″ may belinked to form a substituted or unsubstituted, saturated or unsaturated,cyclic group, and wherein at least one of R⁶⁻⁸ must be hydrogen, and atleast two of R⁶⁻⁸ must not be methyl; purging the reactor with a purgegas; introducing an oxygen-containing or nitrogen-containing source (orcombination thereof) into the reactor; and purging the reactor with thepurge gas, wherein the steps are repeated until a desired thickness offilm is deposited; and wherein the method is conducted at one or moretemperatures ranging from about 25° C. to 600° C.

In some embodiments, the oxygen-containing source employed in the methodis a source selected from the group consisting of an oxygen plasma,ozone, a water vapor, water vapor plasma, nitrogen oxide (e.g., N₂O, NO,NO₂) plasma with or without inert gas, a carbon oxide (e.g., CO₂, CO)plasma and combinations thereof. In certain embodiments, the oxygensource further comprises an inert gas. In these embodiments, the inertgas is selected from the group consisting of argon, helium, nitrogen,hydrogen, and combinations thereof. In an alternative embodiment, theoxygen source does not comprise an inert gas. In yet another embodiment,the oxygen-containing source comprises nitrogen which reacts with thereagents under plasma conditions to provide a silicon oxynitride film.

In some embodiments, the nitrogen-containing source may be introducedinto the reactor in the form of at least one nitrogen-containing sourceand/or may be present incidentally in the other precursors used in thedeposition process. Suitable nitrogen source gases may include, forexample, ammonia, hydrazine, monoalkylhydrazine, dialkylhydrazine,nitrogen, nitrogen/hydrogen, nitrogen/argon plasma, nitrogen/heliumplasma, ammonia plasma, nitrogen plasma, nitrogen/hydrogen plasma,organic amines such as tert-butylamine, dimethylamine, diethylamine,isopropylamine, diethylamine plasma, dimethylamine plasma, trimethylplasma, trimethylamine plasma, ethylenediamine plasma, and analkoxyamine such as ethanolamine plasma and mixture thereof. In certainembodiments, the nitrogen-containing source comprises an ammonia plasma,a plasma comprising nitrogen and argon, a plasma comprising nitrogen andhelium or a plasma comprising hydrogen and nitrogen source gas.

In the embodiments described above and throughout this invention, theinert gas is selected from the group consisting of argon, helium,nitrogen, hydrogen, or combinations thereof. In an alternativeembodiment, the oxygen-containing plasma source does not comprise aninert gas.

One embodiment of the invention relates to uniform and conformalsilicon-containing films such as silicon oxide having at least one ormore of the following attributes: a density of about 2.1 g/cc orgreater, a growth rate of 2.0 Å/cycle or greater, low chemical impurity,and/or high conformality in a thermal atomic layer deposition, a plasmaenhanced atomic layer deposition (ALD) process or a plasma enhancedALD-like process using cheaper, reactive, and more stable siliconprecursor compounds.

The embodiments of the invention can be used alone or in combinationswith each other.

DETAILED DESCRIPTION OF THE INVENTION

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein areillustrative and shall not limit the scope of the invention. Variationsof those preferred embodiments may become apparent to those of ordinaryskill in the art upon reading the foregoing description. The inventorsexpect skilled artisans to employ such variations as appropriate, andthe inventors intend for the invention to be practiced otherwise than asspecifically described herein. Accordingly, this invention includes allmodifications and equivalents of the subject matter recited in theclaims appended hereto as permitted by applicable law. Moreover, anycombination of the above-described elements in all possible variationsthereof is encompassed by the invention unless otherwise indicatedherein or otherwise clearly contradicted by context.

Described herein are methods related to the formation of astoichiometric or nonstoichiometric film or material comprising siliconsuch as, without limitation, a silicon oxide, a carbon-doped siliconoxide film, a silicon oxynitride, a silicon nitride, a carbon-dopedsilicon nitride, a carbon-doped silicon oxynitride film or combinationsthereof with one or more temperatures, of about 600° C. or less, or fromabout 25° C. to about 600° C. and, in some embodiments, from 25° C. toabout 300° C. The films described herein are deposited in a depositionprocess such as an atomic layer deposition (ALD) or in an ALD-likeprocess such as, without limitation, a plasma enhanced ALD (PEALD) or aplasma enhanced cyclic chemical vapor deposition process (PECCVD), aflowable chemical vapor deposition (FCVD), or a plasma enhanced flowablechemical vapor deposition (PEFCVD). The low temperature deposition(e.g., one or more deposition temperatures ranging from about ambienttemperature to 600° C.) methods described herein provide films ormaterials that exhibit at least one or more of the following advantages:a density of about 2.1 g/cc or greater, low chemical impurity, highconformality in a thermal atomic layer deposition, a plasma enhancedatomic layer deposition (ALD) process or a plasma enhanced ALD-likeprocess, an ability to adjust carbon content in the resulting film;and/or films have an etching rate of 5 Angstroms per second (A/sec) orless when measured in 0.5 wt % dilute HF. For carbon-doped silicon oxidefilms, greater than 1% carbon is desired to tune the etch rate to valuesbelow 2 Å/sec in 0.5 wt % dilute HF in addition to other characteristicssuch as, without limitation, a density of about 1.8 g/cc or greater orabout 2.0 g/cc or greater.

The present invention can be practiced using equipment known in the art.For example, the inventive method can use a reactor that is conventionalin the semiconductor manufacturing art.

In one embodiment, the silicon precursor composition described hereincomprises at least one functionalized cyclosilazanes having thefollowing Formulae A, B, C, D, or E:

wherein R¹⁻³ are each independently selected from the group consistingof hydrogen, methyl, and an organoamino group (NR′R″), wherein R′ and R″are each independently selected from the group consisting of hydrogen, aC₁₋₁₀ linear alkyl group, a C₃₋₁₀ branched alkyl group, a C₃₋₁₀ cyclicalkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀ aryl group, and a C₄₋₁₀heterocyclic group, with the proviso that R′ and R″ cannot both behydrogen; R⁴ and R⁵ are each independently selected from the groupconsisting of hydrogen, a C₁₋₁₀ linear alkyl group, a C₃₋₁₀ branchedalkyl group, a C₃₋₁₀ cyclic alkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀aryl group, and a C₄₋₁₀ heterocyclic group; R⁶⁻⁸ are each independentlyselected from the group consisting of hydrogen, methyl, an organoaminogroup (NR′R″) as defined above, a C₃₋₁₀ branched alkyl group, a C₃₋₁₀cyclic alkyl group, a C₂₋₁₀ alkenyl group, a C₄₋₁₀ aryl group, and aC₄₋₁₀ heterocyclic group, with the proviso that R′ and R″ cannot both behydrogen, wherein two or more of substituents R¹⁻⁸, R′, and R″ may belinked to form a substituted or unsubstituted, saturated or unsaturated,cyclic group, and wherein at least one of R⁶⁻⁸ must be hydrogen, and atleast two of R⁶⁻⁸ must not be methyl.

In certain embodiments of the composition described herein furthercomprises a solvent. Exemplary solvents can include, without limitation,ether, tertiary amine, alkyl hydrocarbon, aromatic hydrocarbon, tertiaryaminoether, and combinations thereof. In certain embodiments, thedifference between the boiling point of the silicon precursor and theboiling point of the solvent is 40° C. or less.

In the formulae above and throughout the description, the term “alkyl”denotes a linear or branched functional group having from 1 to 10 carbonatoms. Exemplary linear alkyl groups include, but are not limited to,methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. Exemplarybranched alkyl groups include, but are not limited to, iso-propyl,iso-butyl, sec-butyl, tert-butyl, iso-pentyl, tert-pentyl, iso-hexyl,and neo-hexyl. In certain embodiments, the alkyl group may have one ormore functional groups attached thereto such as, but not limited to, analkoxy group, a dialkylamino group or combinations thereof, attachedthereto. In other embodiments, the alkyl group does not have one or morefunctional groups attached thereto. The alkyl group may be saturated or,alternatively, unsaturated.

In the formulae above and throughout the description, the term “cyclicalkyl” denotes a cyclic functional group having from 3 to 10 carbonatoms. Exemplary cyclic alkyl groups include, but are not limited to,cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups.

In the formulae above and throughout the description, the term “alkenylgroup” denotes a group which has one or more carbon-carbon double bondsand has from 2 to 10 or from 2 to 6 carbon atoms.

In the formulae described herein and throughout the description, theterm “dialkylamino group or alkylamino group” denotes a group which hastwo alkyl groups bonded to a nitrogen atom or one alkyl bonded to anitrogen atom and has from 1 to 10 or from 2 to 6 or from 2 to 4 carbonatoms. Example include but not limited to HNMe, HNBu^(t), NMe₂, NMeEt,NEt₂, NPr^(i) ₂.

In the formulae above and throughout the description, the term “aryl”denotes an aromatic cyclic functional group having from 4 to 10 carbonatoms, from 5 to 10 carbon atoms, or from 6 to 10 carbon atoms.Exemplary aryl groups include, but are not limited to, phenyl, benzyl,chlorobenzyl, tolyl, o-xylyl, 1,2,3-triazolyl, pyrrrolyl, and furanyl.

In the formulae above and throughout the description, the term“heterocyclic” means a non-aromatic saturated monocyclic or multicyclicring system of about 3 to about 10 ring atoms, preferably about 5 toabout 10 ring atoms, in which one or more of the atoms in the ringsystem is/are element(s) other than carbon, for example nitrogen, oxygenor sulfur. Preferred heterocycles contain about 5 to about 6 ring atoms.The prefix aza, oxa or thia before heterocycle means that at least anitrogen, oxygen or sulfur atom respectively is present as a ring atom.The heterocyclic group is optionally substituted.

Exemplary functionalized cyclosilazane precursors are listed in Table 1:

TABLE 1

2,2,4,4,6,6- hexamethylcyclotrisilazane

1-silyl-2,2,4,4,6,6- hexamethylcyclotrisilazane

1-(dimethylaminosilyl)- 2,2,4,4,6,6- hexamethylcyclotrisilazane

1-(dimethylamino- methylsilyl)-2,2,4,4,6,6- hexamethylcyclotrisilazane

1,2,3,4,5,6- hexamethylcyclotrisilazane

2-dimethylamino-1,2,3,4,5,6- hexamethylcyclotrisilazane

1-(dimethylamino- methylsilyl)-2,4,6- trimethylcyclotrisilazane

1,2,3-trisilyl-2,2,4,4,6,6- hexamethylcyclotrisilazane

1,2,3-trisilyl-2,4,6- trimethylcyclotrisilazane

2,2,4,4,6,6-hexamethyl-1,3- dioxa-5-aza-2,4,6- trisilacyclohexane

2,2,4,4,5,6,6-heptamethyl-1, 3-dioxa-5-aza-2,4,6- trisilacyclohexane

5-ethyl-2,2,4,4,6,6- hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane

5-n-propyl-2,2,4,4,6,6- hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane

5-iso-propyl-2,2,4,4,6,6- hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane

5-silyl-2,2,4,4,6,6- hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane

5-methylsilyl-2,2,4,4,6,6- hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane

5-(dimethylaminosilyl)-2,2,4, 4,6,6-hexamethyl-1,3-dioxa- 5-aza-2,4,6-trisilacyclohexane

5-(dimethylamino- methylsilyl)-2,2,4,4,6,6- hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane

In another embodiment of the present invention, a method is describedherein for depositing a silicon-containing film on at least one surfaceof a substrate, wherein the method comprises the steps of:

-   -   a. providing a substrate in a reactor;    -   b. introducing into the reactor at least one silicon precursor        having Formulae A to E as defined above;    -   c. purging the reactor with purge gas;    -   d. introducing oxygen-containing source comprising a plasma into        the reactor; and    -   e. purging the reactor with a purge gas.

In this method, steps b through e are repeated until a desired thicknessof film is deposited on the substrate.

The method of the present invention is conducted via an ALD process thatuses ozone or an oxygen-containing source which comprises a plasmawherein the plasma can further comprise an inert gas such as one or moreof the following: an oxygen plasma with or without inert gas, a watervapor plasma with or without inert gas, a nitrogen oxide (e.g., N₂O, NO,NO₂) plasma with or without inert gas, a carbon oxide (e.g., CO₂, CO)plasma with or without inert gas, and combinations thereof.

The oxygen-containing plasma source can be generated in situ or,alternatively, remotely. In one particular embodiment, theoxygen-containing source comprises oxygen and is flowing, or introducedduring method steps b through d, along with other reagents such aswithout limitation, the at least one silicon precursor and optionally aninert gas.

In certain embodiments, the silicon precursor compounds having FormulaeA to E according to the present invention and compositions comprisingthe silicon precursor compounds having Formulae A to E according to thepresent invention are preferably substantially free of halide ions. Asused herein, the term “substantially free” as it relates to halide ions(or halides) such as, for example, chlorides and fluorides, bromides,and iodides, means less than 5 ppm (by weight), preferably less than 3ppm, and more preferably less than 1 ppm, and most preferably 0 ppm asmeasured by ICP-MS. Chloride-containing impurities are known to act asdecomposition catalysts for the silicon precursor compounds havingFormulae A to E. In certain cases, significant levels of chloride in thefinal product can cause the silicon precursor compounds to degrade. Thegradual degradation of the silicon precursor compounds may directlyimpact the film deposition process making it difficult for thesemiconductor manufacturer to meet film specifications. In addition, theshelf-life or stability is negatively impacted by the higher degradationrate of the silicon precursor compounds thereby making it difficult toguarantee a 1-2 year shelf-life. Therefore, the accelerateddecomposition of the silicon precursor compounds presents safety andperformance concerns related to the formation of these flammable and/orpyrophoric gaseous byproducts.

For those embodiments wherein at least one silicon precursor(s) havingFormulae A to E is (are) used in a composition comprising a solvent, thesolvent or mixture thereof selected does not react with the siliconprecursor. The amount of solvent by weight percentage in the compositionranges from 0.5 wt % by weight to 99.5 wt % or from 10 wt % by weight to75 wt %. In this or other embodiments, the solvent has a boiling point(b.p.) similar to the b.p. of the silicon precursor of Formulae A to Eor the difference between the b.p. of the solvent and the b.p. of thesilicon precursor of Formulae A to E is 40° C. or less, 30° C. or less,or 20° C. or less, or 10° C. Alternatively, the difference between theboiling points ranges from any one or more of the following end-points:0, 10, 20, 30, or 40° C. Examples of suitable ranges of b.p. differenceinclude without limitation, 0 to 40° C., 20° to 30° C., or 10° to 30° C.Examples of suitable solvents in the compositions include, but are notlimited to, an ether (such as 1,4-dioxane, dibutyl ether), a tertiaryamine (such as pyridine, 1-methylpiperidine, 1-ethylpiperidine,N,N′-Dimethylpiperazine, N,N,N′,N′-Tetramethylethylenediamine), anitrile (such as benzonitrile), an alkyl hydrocarbon (such as octane,nonane, dodecane, ethylcyclohexane), an aromatic hydrocarbon (such astoluene, mesitylene), a tertiary aminoether (such asbis(2-dimethylaminoethyl) ether), or mixtures thereof.

Throughout the description, the term “ALD or ALD-like” refers to aprocess including, but not limited to, the following processes: a) eachreactant including a silicon precursor and a reactive gas is introducedsequentially into a reactor such as a single wafer ALD reactor,semi-batch ALD reactor, or batch furnace ALD reactor; b) each reactantincluding the silicon precursor and the reactive gas is exposed to asubstrate by moving or rotating the substrate to different sections ofthe reactor and each section is separated by inert gas curtain, i.e.,spatial ALD reactor or roll to roll ALD reactor.

In certain embodiments, silicon oxide or carbon doped silicon oxidefilms deposited using the methods described herein are formed in thepresence of oxygen-containing source comprising ozone, water (H₂O)(e.g., deionized water, purifier water, and/or distilled water), oxygen(02), oxygen plasma, NO, N₂O, NO₂, carbon monoxide (CO), carbon dioxide(CO₂) and combinations thereof. The oxygen-containing source is passedthrough, for example, either an in situ or remote plasma generator toprovide oxygen-containing plasma source comprising oxygen such as anoxygen plasma, a plasma comprising oxygen and argon, a plasma comprisingoxygen and helium, an ozone plasma, a water plasma, a nitrous oxideplasma, or a carbon dioxide plasma. In certain embodiments, theoxygen-containing plasma source comprises an oxygen source gas that isintroduced into the reactor at a flow rate ranging from about 1 to about2000 standard cubic centimeters (sccm) or from about 1 to about 1000sccm. The oxygen-containing plasma source can be introduced for a timethat ranges from about 0.1 to about 100 seconds. In one particularembodiment, the oxygen-containing plasma source comprises water having atemperature of 10° C. or greater. In embodiments wherein the film isdeposited by a PEALD or a plasma enhanced cyclic CVD process, theprecursor pulse can have a pulse duration that is greater than 0.01seconds (e.g., about 0.01 to about 0.1 seconds, about 0.1 to about 0.5seconds, about 0.5 to about 10 seconds, about 0.5 to about 20 seconds,about 1 to about 100 seconds) depending on the ALD reactor's volume, andthe oxygen-containing plasma source can have a pulse duration that isless than 0.01 seconds (e.g., about 0.001 to about 0.01 seconds).

The deposition methods disclosed herein may involve one or more purgegases. The purge gas, which is used to purge away unconsumed reactantsand/or reaction byproducts, is an inert gas that does not react with theprecursors, and thereby forming a composition comprising the foregoing.Exemplary purge gases include, but are not limited to, argon (Ar),nitrogen (N₂), helium (He), neon, hydrogen (H₂), and mixtures thereof.In certain embodiments, a purge gas such as Ar is supplied into thereactor at a flow rate ranging from about 10 to about 2000 sccm forabout 0.1 to 1000 seconds, thereby purging the unreacted material andany byproduct that may remain in the reactor.

The respective step of supplying the precursors, oxygen source, and/orother precursors, source gases, and/or reagents may be performed bychanging the time for supplying them to change the stoichiometriccomposition of the resulting dielectric film.

Energy is applied to the at least one of the silicon precursors ofFormulae A to E, oxygen containing source, or combination thereof toinduce reaction and to form the dielectric film or coating on thesubstrate. Such energy can be provided by, but not limited to, thermal,plasma, pulsed plasma, helicon plasma, high density plasma, inductivelycoupled plasma, X-ray, e-beam, photon, remote plasma methods, andcombinations thereof. In certain embodiments, a secondary RF frequencysource can be used to modify the plasma characteristics at the substratesurface. In embodiments wherein the deposition involves plasma, theplasma-generated process may comprise a direct plasma-generated processin which plasma is directly generated in the reactor, or alternatively,a remote plasma-generated process in which plasma is generated outsideof the reactor and supplied into the reactor.

The at least one silicon precursor may be delivered to the reactionchamber such as a plasma enhanced cyclic CVD or PEALD reactor or a batchfurnace type reactor in a variety of ways. In one embodiment, a liquiddelivery system may be utilized. In an alternative embodiment, acombined liquid delivery and flash vaporization process unit may beemployed, such as, for example, the turbo vaporizer manufactured by MSPCorporation of Shoreview, Minn., to enable low volatility materials tobe volumetrically delivered, which leads to reproducible transport anddeposition without thermal decomposition of the precursor. In liquiddelivery formulations, the precursors described herein may be deliveredin neat liquid form, or alternatively, may be employed in solventformulations or compositions comprising same. Thus, in certainembodiments the precursor formulations may include solvent component(s)of suitable character as may be desirable and advantageous in a givenend use application to form a film on a substrate.

As previously mentioned, the purity level of the at least one siliconprecursor is sufficiently high enough to be acceptable for reliablesemiconductor manufacturing. In certain embodiments, the at least onesilicon precursor described herein comprise less than 2% by weight, orless than 1% by weight, or less than 0.5% by weight of one or more ofthe following impurities: free amines, free halides or halogen ions, andhigher molecular weight species. Higher purity levels of the siliconprecursor described herein can be obtained through one or more of thefollowing processes: purification, adsorption, and/or distillation.

In one embodiment of the method described herein, a plasma enhancedcyclic deposition process such as PEALD-like or PEALD may be usedwherein the deposition is conducted using the at least one siliconprecursor and an oxygen plasma source. The PEALD-like process is definedas a plasma enhanced cyclic CVD process but still provides highconformal silicon and oxygen-containing films.

In certain embodiments, the gas lines connecting from the precursorcanisters to the reaction chamber are heated to one or more temperaturesdepending upon the process requirements and the container of the atleast one silicon precursor is kept at one or more temperatures forbubbling. In other embodiments, a solution comprising the at least onesilicon precursor is injected into a vaporizer kept at one or moretemperatures for direct liquid injection.

A flow of argon and/or other gas may be employed as a carrier gas tohelp deliver the vapor of the at least one silicon precursor to thereaction chamber during the precursor pulsing. In certain embodiments,the reaction chamber process pressure is about 50 mTorr to 10 Torr. Inother embodiments, the reaction chamber process pressure can be up to760 Torr (e.g., about 50 mtorr to about 100 Torr).

In a typical PEALD or a PEALD-like process such as a PECCVD process, thesubstrate such as a silicon oxide substrate is heated on a heater stagein a reaction chamber that is exposed to the silicon precursor initiallyto allow the complex to chemically adsorb onto the surface of thesubstrate.

A purge gas such as argon purges away unabsorbed excess complex from theprocess chamber. After sufficient purging, an oxygen source may beintroduced into reaction chamber to react with the absorbed surfacefollowed by another gas purge to remove reaction by-products from thechamber. The process cycle can be repeated to achieve the desired filmthickness. In some cases, pumping can replace a purge with inert gas orboth can be employed to remove unreacted silicon precursors.

In this or other embodiments, it is understood that the steps of themethods described herein may be performed in a variety of orders, may beperformed sequentially, may be performed concurrently (e.g., during atleast a portion of another step), and any combination thereof. Therespective step of supplying the precursors and the oxygen source gases,for example, may be performed by varying the duration of the time forsupplying them to change the stoichiometric composition of the resultingdielectric film. Also, purge times after precursor or oxidant steps canbe minimized to <0.1 s so that throughput is improved.

In one particular embodiment, the method described herein deposits ahigh quality silicon-containing film such as, for example, a silicon andoxygen-containing film, on a substrate. The method comprises thefollowing steps:

-   -   a. providing a substrate in a reactor;    -   b. introducing into the reactor at least one silicon precursor        having the Formulae A to E described herein;    -   c. purging reactor with purge gas to remove at least a portion        of the unabsorbed precursors;    -   d. introducing an oxygen-containing plasma source into the        reactor and    -   e. purging reactor with purge gas to remove at least a portion        of the unreacted oxygen source,        wherein steps b through e are repeated until a desired thickness        of the silicon-containing film is deposited.

Another method disclosed herein forms a carbon doped silicon oxide filmusing a silicon precursor compound having the chemical structurerepresented by Formulae A to E as defined above plus an oxygen source.

Another exemplary process is described as follows:

-   -   a. providing a substrate in a reactor;    -   b. contacting vapors generated from at least one silicon        precursor compound having a structure represented by Formulae A        to E as defined above, with or without co-flowing an oxygen        source to chemically absorb the precursors on the heated        substrate;    -   c. purging away any unabsorbed precursors;    -   d. Introducing an oxygen source on the heated substrate to react        with the absorbed precursors; and,    -   e. purging away any unreacted oxygen source,        wherein steps b through e are repeated until a desired thickness        is achieved.

In another particular embodiment, the method described herein deposits ahigh quality silicon-containing film such as, for example, a siliconnitride film, on a substrate. The method comprises the following steps:

-   -   a. providing a substrate in a reactor;    -   b. introducing into the reactor at least one silicon precursor        having the Formulae A to E described herein;    -   c. purging reactor with purge gas to remove at least a portion        of the unabsorbed precursors;    -   d. introducing an nitrogen-containing plasma source into the        reactor and    -   e. purging reactor with purge gas to remove at least a portion        of the unreacted nitrogen source,        wherein steps b through e are repeated until a desired thickness        of the silicon-containing film is deposited.

Another exemplary process is described as follows:

-   -   a. providing a substrate in a reactor;    -   b. contacting vapors generated from at least one silicon        precursor compound having a structure represented by Formulae A        to E as defined above, with or without co-flowing a nitrogen        source to chemically absorb the precursors on the heated        substrate;    -   c. purging away any unabsorbed precursors;    -   d. Introducing a nitrogen source on the heated substrate to        react with the absorbed precursors; and,    -   e. purging away any unreacted nitrogen source,        wherein steps b through e are repeated until a desired thickness        is achieved.

Various commercial ALD reactors such as single wafer, semi-batch, batchfurnace or roll to roll reactor can be employed for depositing the solidsilicon oxide, silicon nitride, silicon oxynitride, carbon doped siliconnitride, carbon doped silicon oxynitride, or carbon doped silicon oxide.

Process temperature for the method described herein use one or more ofthe following temperatures as endpoints: 0, 25, 50, 75, 100, 125, 150,175, 200, 225, 250, 275, 300° C., 325° C., 350° C., 375° C., 400° C.,425° C., 450° C., 500° C., 525° C., 550° C. Exemplary temperature rangesinclude, but are not limited to the following: from about 0° C. to about300° C.; or from about 25° C. to about 300° C.; or from about 50° C. toabout 290° C.; or from about 25° C. to about 250° C., or from about 25°C. to about 200° C.

In another aspect, there is provided a method for depositing asilicon-containing film via flowable chemical vapor deposition (FCVD),the method comprising:

placing a substrate comprising a surface feature into a reactor whereinthe substrate is maintained at one or more temperatures ranging fromabout −20° C. to about 400° C. and a pressure of the reactor ismaintained at 100 torr or less;

introducing at least one compound selected from the group consisting ofFormulae A to E:

providing an oxygen source into the reactor to react with the at leastone compound to form a film and cover at least a portion of the surfacefeature;

annealing the film at one or more temperatures of about 100° C. to 1000°C. to coat at least a portion of the surface feature; and

treating the substrate with an oxygen source at one or more temperaturesranging from about 20° C. to about 1000° C. to form thesilicon-containing film on at least a portion of the surface feature.

In another aspect, there is provided a method for depositing asilicon-containing film via flowable chemical vapor deposition (FCVD),the method comprising:

placing a substrate comprising a surface feature into a reactor whereinthe substrate is maintained at one or more temperatures ranging fromabout −20° C. to about 400° C. and a pressure of the reactor ismaintained at 100 torr or less;

introducing at least one compound selected from the group consisting ofFormulae A to E:

providing a nitrogen source into the reactor to react with the at leastone compound to form a film and cover at least a portion of the surfacefeature;

annealing the film at one or more temperatures of about 100° C. to 1000°C. to coat at least a portion of the surface feature; and

treating the substrate with an oxygen source at one or more temperaturesranging from about 20° C. to about 1000° C. to form thesilicon-containing film on at least a portion of the surface feature.

In certain embodiments, the oxygen source is selected from the groupconsisting of water vapors, water plasma, ozone, oxygen, oxygen plasma,oxygen/helium plasma, oxygen/argon plasma, nitrogen oxides plasma,carbon dioxide plasma, hydrogen peroxide, organic peroxides, andmixtures thereof. In other embodiments, the nitrogen source is selectedfrom the group consisting of for example, ammonia, hydrazine,monoalkylhydrazine, dialkylhydrazine, nitrogen, nitrogen/hydrogen,nitrogen/argon plasma, nitrogen/helium plasma, ammonia plasma, nitrogenplasma, nitrogen/hydrogen plasma, organic amines such astert-butylamine, dimethylamine, diethylamine, isopropylamine,diethylamine plasma, dimethylamine plasma, trimethyl plasma,trimethylamine plasma, ethylenediamine plasma, and an alkoxyamine suchas ethanolamine plasma, and mixtures thereof. In yet other embodiments,the nitrogen-containing source comprises an ammonia plasma, a plasmacomprising nitrogen and argon, a plasma comprising nitrogen and heliumor a plasma comprising hydrogen and nitrogen source gas. In this orother embodiments, the method steps are repeated until the surfacefeatures are filled with the silicon-containing film. In embodimentswherein water vapor is employed as an oxygen source, the substratetemperature ranges from about −20° C. to about 40° C. or from about −10°C. to about 25° C.

In a still further embodiment of the method described herein, the filmor the as-deposited film deposited from ALD, ALD-like, PEALD, PEALD-likeor FCVD is subjected to a treatment step (post deposition). Thetreatment step can be conducted during at least a portion of thedeposition step, after the deposition step, and combinations thereof.Exemplary treatment steps include, without limitation, treatment viahigh temperature thermal annealing; plasma treatment; ultraviolet (UV)light treatment; laser; electron beam treatment and combinations thereofto affect one or more properties of the film.

The films deposited with the silicon precursors having Formulae A to Edescribed herein, when compared to films deposited with previouslydisclosed silicon precursors under the same conditions, have improvedproperties such as, without limitation, a wet etch rate that is lowerthan the wet etch rate of the film before the treatment step or adensity that is higher than the density prior to the treatment step. Inone particular embodiment, during the deposition process, as-depositedfilms are intermittently treated. These intermittent or mid-depositiontreatments can be performed, for example, after each ALD cycle, afterevery a certain number of ALD, such as, without limitation, one (1) ALDcycle, two (2) ALD cycles, five (5) ALD cycles, or after every ten (10)or more ALD cycles.

The precursors of Formulae A to E exhibit a growth rate of 1.0 Å/cycleor greater, preferably a growth rate of 1.5 Å/cycle or greater, mostpreferable a growth rate of 2.0 Å/cycle or greater.

In an embodiment wherein the film is treated with a high temperatureannealing step, the annealing temperature is at least 100° C. or greaterthan the deposition temperature. In this or other embodiments, theannealing temperature ranges from about 400° C. to about 1000° C. Inthis or other embodiments, the annealing treatment can be conducted in avacuum (<760 Torr), inert environment or in oxygen containingenvironment (such as H₂O, N₂O, NO₂ or O₂).

In an embodiment wherein the film is treated to UV treatment, film isexposed to broad band UV or, alternatively, an UV source having awavelength ranging from about 150 nanometers (nm) to about 400 nm. Inone particular embodiment, the as-deposited film is exposed to UV in adifferent chamber than the deposition chamber after a desired filmthickness is reached.

In an embodiment where in the film is treated with a plasma, passivationlayer such as SiO₂ or carbon doped SiO₂ is deposited to prevent chlorineand nitrogen contamination to penetrate into film in the subsequentplasma treatment. The passivation layer can be deposited using atomiclayer deposition or cyclic chemical vapor deposition.

In an embodiment wherein the film is treated with a plasma, the plasmasource is selected from the group consisting of hydrogen plasma, plasmacomprising hydrogen and helium, plasma comprising hydrogen and argon.Hydrogen plasma lowers film dielectric constant and boost the damageresistance to following plasma ashing process while still keeping thecarbon content in the bulk almost unchanged.

Without intending to be bound by a particular theory, it is believedthat the silicon precursor compound having a chemical structurerepresented by Formulae A to E as defined above can be anchored viabreaking an Si—N bond, organoaminosilyl group, or silazane group withhydroxyl on substrate surface to provide Si—O—Si′ fragments wherein theSi′ fragment is bonded to a nitrogen atom that is part of the 6-memberedring which comprises at least two additional silicon atoms, thusincreasing the growth rate of silicon oxide or carbon doped siliconoxide compared to conventional silicon precursors such asbis(tert-butylamino)silane or bis(diethylamino)silane having only onesilicon atom. With the functionalized cyclosilazanes having Formulae Ato E, as many as 3 to 6 silicon atoms can be anchored to the substrateper molecule during a silicon precursor pulse step.

In certain embodiments, the silicon precursors having Formulae A to E asdefined above can also be used as a dopant for metal containing films,such as but not limited to, metal oxide films or metal nitride films. Inthese embodiments, the metal containing film is deposited using an ALDor CVD process such as those processes described herein using metalalkoxide, metal amide, or volatile organometallic precursors. Examplesof suitable metal alkoxide precursors that may be used with the methoddisclosed herein include, but are not limited to, group 3 to 6 metalalkoxide, group 3 to 6 metal complexes having both alkoxy and alkylsubstituted cyclopentadienyl ligands, group 3 to 6 metal complexeshaving both alkoxy and alkyl substituted pyrrolyl ligands, group 3 to 6metal complexes having both alkoxy and diketonate ligands; group 3 to 6metal complexes having both alkoxy and ketoester ligands.

Examples of suitable metal amide precursors that may be used with themethod disclosed herein include, but are not limited to,tetrakis(dimethylamino)zirconium (TDMAZ),tetrakis(diethylamino)zirconium (TDEAZ),tetrakis(ethylmethylamino)zirconium (TEMAZ),tetrakis(dimethylamino)hafnium (TDMAH), tetrakis(diethylamino)hafnium(TDEAH), and tetrakis(ethylmethylamino)hafnium (TEMAH),tetrakis(dimethylamino)titanium (TDMAT), tetrakis(diethylamino)titanium(TDEAT), tetrakis(ethylmethylamino)titanium (TEMAT), tert-butyliminotri(diethylamino)tantalum (TBTDET), tert-butyliminotri(dimethylamino)tantalum (TBTDMT), tert-butyliminotri(ethylmethylamino)tantalum (TBTEMT), ethyliminotri(diethylamino)tantalum (EITDET), ethyliminotri(dimethylamino)tantalum (EITDMT), ethyliminotri(ethylmethylamino)tantalum (EITEMT), tert-amyliminotri(dimethylamino)tantalum (TAIMAT), tert-amyliminotri(diethylamino)tantalum, pentakis(dimethylamino)tantalum,tert-amylimino tri(ethylmethylamino)tantalum,bis(tert-butylimino)bis(dimethylamino)tungsten (BTBMW),bis(tert-butylimino)bis(diethylamino)tungsten,bis(tert-butylimino)bis(ethylmethylamino)tungsten, and combinationsthereof. Examples of suitable organometallic precursors that may be usedwith the method disclosed herein include, but are not limited to, group3 metal cyclopentadienyls or alkyl cyclopentadienyls. Exemplary Group 3to 6 metals herein include, but not limited to, Y, La, Ce, Pr, Nd, Sm,Eu, Gd, Tb, Dy, Er, Yb, Lu, Ti, Hf, Zr, V, Nb, Ta, Cr, Mo, and W.

In certain embodiments, the silicon-containing films described hereinhave a dielectric constant of 6 or less, 5 or less, 4 or less, and 3 orless. In these or other embodiments, the films can a dielectric constantof about 5 or below, or about 4 or below, or about 3.5 or below.However, it is envisioned that films having other dielectric constants(e.g., higher or lower) can be formed depending upon the desired end-useof the film. An example of silicon-containing film that is formed usingthe silicon precursors having Formulae A to E precursors and processesdescribed herein has the formulation Si_(x)O_(y)C_(z)N_(v)H_(w) whereinSi ranges from about 10% to about 40%; 0 ranges from about 0% to about65%; C ranges from about 0% to about 75% or from about 0% to about 50%;N ranges from about 0% to about 75% or from about 0% to 50%; and Hranges from about 0% to about 50% atomic percent weight % whereinx+y+z+v+w=100 atomic weight percent, as determined for example, by XPSor other means. Another example of the silicon containing film that isformed using the silicon precursors of Formulae A to E and processesdescribed herein is silicon carbonitride wherein the carbon content isfrom 1 at % to 80 at % measured by XPS. In yet, another example of thesilicon containing film that is formed using the silicon precursorshaving Formulae A to E and processes described herein is amorphoussilicon wherein both sum of nitrogen and carbon contents is <10 at %,preferably <5 at %, most preferably <1 at % measured by XPS.

As mentioned previously, the method described herein may be used todeposit a silicon-containing film on at least a portion of a substrate.Examples of suitable substrates include but are not limited to, silicon,SiO₂, Si₃N₄, OSG, FSG, silicon carbide, hydrogenated silicon carbide,silicon nitride, hydrogenated silicon nitride, silicon carbonitride,hydrogenated silicon carbonitride, boronitride, antireflective coatings,photoresists, germanium, germanium-containing, boron-containing, Ga/As,a flexible substrate, organic polymers, porous organic and inorganicmaterials, metals such as copper and aluminum, and diffusion barrierlayers such as but not limited to TiN, Ti(C)N, TaN, Ta(C)N, Ta, W, orWN. The films are compatible with a variety of subsequent processingsteps such as, for example, chemical mechanical planarization (CMP) andanisotropic etching processes.

The deposited films have applications, which include, but are notlimited to, computer chips, optical devices, magnetic informationstorages, coatings on a supporting material or substrate,microelectromechanical systems (MEMS), nanoelectromechanical systems,thin film transistor (TFT), light emitting diodes (LED), organic lightemitting diodes (OLED), IGZO, and liquid crystal displays (LCD).Potential use of resulting solid silicon oxide or carbon doped siliconoxide include, but not limited to, shallow trench insulation, interlayer dielectric, passivation layer, an etch stop layer, part of a dualspacer, and sacrificial layer for patterning.

The methods described herein provide a high quality silicon oxide,silicon nitride, silicon oxynitride, carbon doped silicon nitride,carbon doped silicon oxynitride, or carbon-doped silicon oxide film. Theterm “high quality” means a film that exhibits one or more of thefollowing characteristics: a density of about 2.1 g/cc or greater, 2.2g/cc or greater, 2.25 g/cc or greater; a wet etch rate that is 2.5 Å/sor less, 2.0 Å/s or less, 1.5 Å/s or less, 1.0 Å/s or less, 0.5 Å/s orless, 0.1 Å/s or less, 0.05 Å/s or less, 0.01 Å/s or less as measured ina solution of 1:100 of HF to water dilute HF (0.5 wt % dHF) acid, anelectrical leakage of about 1 or less e-8 Å/cm² up to 6 MV/cm); ahydrogen impurity of about 5 e20 at/cc or less as measured by SIMS; andcombinations thereof. With regard to the etch rate, a thermally grownsilicon oxide film has 0.5 Å/s etch rate in 0.5 wt % Hf.

In certain embodiments, one or more silicon precursors having Formulae Ato E described herein can be used to form silicon and oxygen containingfilms that are solid and are non-porous or are substantially free ofpores.

The following examples illustrate the method for depositing siliconoxide films described herein and are not intended to limit the appendedclaims.

EXAMPLES

Thermal Atomic Layer Deposition of silicon oxide films were performed ona laboratory scale ALD processing tool. The silicon precursor wasdelivered to the chamber by vapor draw. All gases (e.g., purge andreactant gas or precursor and oxygen source) were preheated to 100° C.prior to entering the deposition zone. Gases and precursor flow rateswere controlled with ALD diaphragm valves with high speed actuation. Thesubstrates used in the deposition were 12-inch-long silicon strips. Athermocouple is attached on the sample holder to confirm substratetemperature. Depositions were performed using ozone as oxygen sourcegas. Normal deposition process and parameters are shown in Table 2.

TABLE 2 Process for Thermal Atomic Layer Deposition of Silicon OxideFilms with Ozone as Oxygen Source on the Laboratory Scale ALD ProcessingTool. Step 1 6 sec Evacuate reactor <100 mT Step 2 variable Dose Siliconprecursor Reactor pressure typically <2 Torr Step 3 6 sec Purge reactorwith nitrogen Flow 1.5 slpm N₂ Step 4 6 sec Evacuate reactor <100 mTStep 5 variable Dose oxygen source ozone Step 6 6 sec Purge reactor withnitrogen Flow 1.5 slpm N₂

Plasma enhanced ALD (PEALD) was performed on a commercial lateral flowreactor (300 mm PEALD tool manufactured by ASM) equipped with 27.1 MHzdirect plasma capability with 3.5 mm fixed spacing between electrodes.The laminar flow chamber design utilizes outer and inner chambers whichhave independent pressure settings. The inner chamber is the depositionreactor in which all reactant gases (e.g. precursor, argon) were mixedin the manifold and delivered to the process reactor. Argon gas was usedto maintain reactor pressure in the outer chamber. Precursors wereliquids maintained in stainless steel bubblers and delivered to thechamber with Ar carrier gas (typically set at 200 sccm flow). Alldepositions reported in this study were done on native oxide containingSi substrates of 8-12 Ohm-cm. Thickness and refractive indices of thefilms were measured using a FilmTek 2000SE ellipsometer. The growth rateper cycle (GPC) is calculated by dividing the measured thickness ofresulting silicon oxide film by the number of total ALD/PEALD cycles.

Example 1. Synthesis of1-(dimethylaminomethylsilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane(prophetic)

1-methylsilyl-2,2,4,4,6,6-hexamethylcyclotrisilazane is combined withdimethylamine in THF solvent in a round-bottom flask. While stirring, 1mol % Ru₃(CO)₁₂ catalyst is added. The reaction mixture is stirred for 1day at room temperature while allowing the H₂ gas byproduct to vent. Thereaction mixture is purified by vacuum-distillation to provide1-(dimethylaminomethylsilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane.

Example 2. Synthesis of2-dimethylamino-1,2,3,4,5,6-hexamethylcyclotrisilazane

To a mixture of 1,2,3,4,5,6-hexamethylcyclotrisilazane (200 g, 0.91mmol) and Ru₃(CO)₁₂ catalyst (1.45 g, 0.00227 mol) stirring in a 1 literround bottom flask was added dimethylamine (230 mL of 2.0 M solution inTHF, 0.46 mol) in 3 separate portions over the course of 6 hours. Thereaction mixture was stirred for 1 day at room temperature whileallowing the H₂ gas byproduct to vent. The volatiles werevacuum-transferred in a flask-to-flask apparatus with the receiver flaskchilled to −78° C. The condensed volatiles were purified byvacuum-distillation to provide2-dimethylamino-1,2,3,4,5,6-hexamethylcyclotrisilazane. GC-MS showed thefollowing peaks: 262 (M+), 247 (M-15), 231, 218, 202, 189, 175, 159,145, 131, 118, 102, 88, 72.

Example 3. Synthesis of1,2,3-trisilyl-2,2,4,4,6,6-hexamethylcyclotrisilazane (prophetic)

2,2,4,4,6,6-hexamethylcyclotrisilazane is combined with 3 equivalents oftriethylamine in hexanes solvent and chilled to −50° C. 3 equivalents ofmonochlorosilane is then condensed slowly into the reaction vessel whilestirring at −50° C. The resulting slurry is allowed to warm slowly toroom temperature while stirring. The solids are removed via filtrationand the solvent and other low-boilers are removed under reducedpressure. The crude product is purified via vacuum-distillation toprovide 1,2,3-trisilyl-2,2,4,4,6,6-hexamethylcyclotrisilazane.

Example 4. Synthesis of2,2,4,4,5,6,6-heptamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane(prophetic)

1,1,1,2,3,3,3-heptamethyldisilazane is combined with 1 equivalent of1,5-dichloro -1,1,3,3,5,5-hexamethyltrisiloxane in the presence ofcatalytic amount of pyridine. After the reaction is determined to becomplete by GC analysis, the crude reaction mixture is purified byvacuum distillation to provide2,2,4,4,5,6,6-heptamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane.

Example 5. Synthesis of5-(dimethylaminosilyl)-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane (prophetic)

Dimethylamine is added as a 2.0 M solution in THF to a stirred mixtureof 5-silyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane and 0.1mol % Ru₃(CO)₁₂ catalyst. The mixture is allowed to stir for 1 day atroom temperature, allowing for the H₂ gas byproduct to vent. Thereaction mixture is purified by vacuum-distillation to provide5-(dimethylaminosilyl)-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane.

Example 6. Synthesis of5-iso-propyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane

A solution of 1,5-dichloro-1,1,3,3,5,5-hexamethyltrisiloxane (0.5 g,0.0018 mol) in pentane (5 mL) is added dropwise to a stirred solution ofiso-propylamine (0.40 g, 0.0068 mol) in pentane (4 mL). The resultingwhite slurry was allowed to stir overnight. The solids were removed byfiltration and the resulting filtrate was determined by GC-MS analysisto contain5-iso-propyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexaneas one of the products. GC-MS showed the following peaks: 262 (M+), 248,234, 218, 207, 193, 177, 160, 147, 133, 119, 110, 96, 88, 73.

Example 7. Synthesis of5-n-propyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane

A solution of n-propylamine (0.30 g, 0.0051 mol) in hexanes (4 mL) wasadded dropwise to a stirred mixture of,5-dichloro-1,1,3,3,5,5-hexamethyltrisiloxane (0.5 g, 0.0018 mol) andtriethylamine (0.40, 0.0020 mol) in hexanes (4 mL). The resulting slurrywas stirred overnight. The solids were removed by filtration and theresulting filtrate was determined by GC-MS to contain5-n-propyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexaneas one of the products. GC-MS showed the following peaks: 262 (M+), 248,234, 218, 207, 193, 177, 160, 147, 133, 119, 110, 96, 88, 73.

Example 8. Synthesis of1-(di-iso-propylaminosilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane

Under the protection of nitrogen atmosphere, 116 mL of butyllithiumsolution (2.5 M in hexanes, 0.29 mol) was added dropwise to a stirredsolution of 2,2,4,4,6,6-hexamethylcyclotrisilazane (66 g, 0.30 mol) inhexanes (140 mL) at −30° C. After the addition is complete, the reactionwas allowed to warm to room temperature and stir for 2 hours. Theresulting reaction mixture was then chilled to −30° C. To this mixturewas added (di-iso-propylamino)chlorosilane (48 g, 0.29 mol) dropwise viaaddition funnel at −30° C. The reaction mixture was allowed to warm toroom temperature while stirring. The white solids were removed viafiltration and the solvent removed under reduced pressure. The crudeproduct was purified by vacuum-distillation to provide the desiredproduct, 1-(di-iso-propylaminosilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane. GC-MS showed the followingpeaks: 349 (M+), 334 (M-15), 318, 306, 292, 276, 248, 234, 218, 203,188, 175, 159, 142, 130, 116, 100, 86, 73.

Examples 9-11: Synthesis of Additional Functionalized CyclosilazanePrecursor Compounds

Additional functionalized cyclosilazane precursor compounds were madevia similar fashion as Example 8 and were characterized by GC-MS. Themolecular weight (MW), the structure, and corresponding major MSfragmentation peaks of each compound are provided in Table 3 to confirmtheir identification.

TABLE 3 Ex. Precursor Name MW Structure MS Peaks  91-(dimethylaminosilyl)- 2,2,4,4,6,6- hexamethylcyclotrisilazane 292.68

291, 277, 261, 248, 234, 218, 203, 189, 174, 160, 143, 131, 116, 100,86, 73 10 1-(iso-propylaminosilyl)- 2,2,4,4,6,6-hexamethylcyclotrisilazane 306.71

306, 291, 275, 261, 248, 234, 218, 203, 188, 174, 159, 146, 138, 130,116, 100, 86, 73 11 1-(methylaminosilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane 278.65

277, 263, 248, 234, 219, 203, 189, 174, 160, 143, 131, 116, 100, 86, 74

Comparative Example 12a: Thermal Atomic Layer Deposition of SiliconOxide Films with Hexamethyldisilazane (HMDSZ

Atomic layer deposition of silicon oxide films was conducted using HMDSZas the silicon precursor. The depositions were performed on thelaboratory scale ALD processing tool. The silicon precursor wasdelivered to the chamber by vapor draw. Deposition process andparameters are provided in Table 2. Steps 1 to 6 are repeated for manycycles until a desired thickness is reached. The process parameters ofthe depositions and results are provided in Table 4.

TABLE 4 Thermal ALD Deposition Parameters and Deposition Results withHMDSZ Deposition Precursor Pulse Ozone time Temperature (° C.) (seconds)(seconds) GPC (Å/cycle) 600  8 s 4 0.42 600 16 s 4 0.62

Comparative Example 12b. PEALD Silicon Oxide Using Hexamethyldisilazane(HMDSZ) in Laminar Flow Reactor with 27.1 MHz Plasma

Depositions were performed with HMDSZ as silicon precursor and O₂ plasmaunder conditions given in Table 5. HMDSZ was delivered to the chamber by100 sccm Ar carrier gas. Steps b to e were repeated many times to get adesired thickness of silicon oxide for metrology. The film depositionparameters and deposition GPC and wafer uniformity are shown in Table 6.The deposition wafer shows bad uniformity and very low GPC.

TABLE 5 Process for PEALD Silicon Oxide Deposition in the CommercialLateral Flow PEALD Reactor with HMDSZ Step a Introduce Si wafer to thereactor Deposition temperature = 100° C. b Introduce silicon precursorto the Precursor pulse = 1 seconds reactor Carrier gas 100 sccm Ar;Process gas Argon flow = 600 sccm Reactor pressure = 3 Torr c Purgesilicon precursor with inert Argon flow = 600 sccm gas (argon) Argonflow time = 4 seconds Reactor pressure = 3 Torr d Oxidation using plasmaArgon flow = 600 sccm Oxygen flow = 100 sccm Plasma power = 800 W Plasmatime = 1 seconds Reactor pressure = 3 Torr e Purge O₂ plasma Plasma offArgon flow = 600 sccm Argon flow time = 2 seconds Reactor pressure = 3Torr

TABLE 6 PEALD Silicon Oxide Film Deposition Parameters and DepositionGPC by HMDSZ Dep T Reactor Precursor O₂ Plasma O₂ Plasma GPC Uniformity(° C.) Pressure (Torr) Flow (s) Time (s) Power (W) (Å/cycle) (%) 100 3 11 800 0.26 24

Example 13: Thermal Atomic Layer Deposition of Silicon Oxide Films with2,2,4,4,6,6-hexamethylcycotrisilazane

Atomic layer deposition of silicon oxide films was conducted using2,2,4,4,6,6-hexamethylcycotrisilazane as the silicon precursor. Thedepositions were performed on the laboratory scale ALD processing tool.The silicon precursor was delivered to the chamber by vapor draw.Deposition process and parameters are provided in Table 2. Steps 1 to 6are repeated many times until a desired thickness is reached. Theprocess parameters of the depositions and results are provided in Table7.

TABLE 7 Thermal ALD Deposition Parameters and Deposition Results with2,2,4,4,6,6-hexamethylcycotrisilazane Deposition Precursor Pulse Ozonetime Temperature (° C.) (seconds) (seconds) GPC (Å/cycle) 500 12 24 1.69500 24 24 1.89 600 24 24 2.06

Example 14. PEALD Silicon Oxide Using2,2,4,4,6,6-Hexamethylcycotrisilazane in Laminar Flow Reactor with 27.1MHz Plasma

Depositions were performed with 2,2,4,4,6,6-hexamethylcycotrisilazane assilicon precursor and O₂ plasma under conditions as described in Table8. Precursor was delivered to chamber with carrier gas Ar flow of 200sccm. Steps b to e were repeated many times to get a desired thicknessof silicon oxide for metrology. The film deposition parameters anddeposition GPC are shown in Table 9. It can be seen that GPC showssaturation with precursor pulse of 8 seconds and longer.

TABLE 8 Process for PEALD Silicon Oxide Deposition in the CommercialLateral Flow PEALD Reactor with 2,2,4,4,6,6-hexamethylcycotrisilazaneStep A Introduce Si wafer to the reactor Deposition temperature = 100°C. or 300° C. B Introduce silicon precursor to the Precursor pulse =variable reactor seconds Carrier gas 200 sccm Ar; Process gas Argon flow= 300 sccm Reactor pressure = 3 Torr C Purge silicon precursor withinert Argon flow = 300 sccm gas (argon) Argon flow time = 10 secondsReactor pressure = 3 Torr D Oxidation using plasma Argon flow = 300 sccmOxygen flow = 100 sccm Plasma power = 200 Watts Plasma time = 5 secondsReactor pressure = 3 Torr E Purge O₂ plasma Plasma off Argon flow = 300sccm Argon flow time = 2 seconds Reactor pressure = 3 Torr

TABLE 9 PEALD Silicon Oxide Film Deposition Parameters and DepositionGPC by 2,2,4,4,6,6-hexamethylcycotrisilazane Reactor Oxygen OxygenProcess Dep T Pressure Precursor Plasma Plasma GPC Uniformity Condition(° C.) (Torr) flow (s) time (s) Power (W) (Å/cycle) (%) 1 300 3 1 5 2000.92 5.2 2 300 3 2 5 200 1.14 3.4 3 300 3 4 5 200 1.34 2.6 4 300 3 8 5200 1.50 2.6 5 300 3 16 5 200 1.64 1.7 6 300 3 32 5 200 1.57 1.4

Example 15. PEALD Silicon Oxide Using1,2,3,4,5,6-Hexamethylcycotrisilazane in Laminar Flow Reactor with 27.1MHz Plasma

Depositions were performed with 1,2,3,4,5,6-hexamethylcycotrisilazane assilicon precursor and O₂ plasma under conditions as described above inTable 8. Precursor was delivered to chamber with carrier gas Ar flow of200 sccm. Steps b to e were repeated many times to get a desiredthickness of silicon oxide for metrology. The film deposition parametersand deposition GPC are shown in Table 10.

TABLE 10 PEALD Silicon Oxide Film Deposition Parameters and DepositionGPC by 1,2,3,4,5,6-hexamethylcycotrisilazane Reactor Oxygen OxygenProcess Dep T Pressure Precursor Plasma Plasma GPC Uniformity Condition(° C.) (Torr) flow (s) time (s) Power (W) (Å/cycle) (%) 1 300 3 1 5 2001.20 2.3 2 300 3 2 5 200 1.38 1.9 3 300 3 4 5 200 1.56 1.8 4 300 3 8 5200 1.67 1.6 5 100 3 1 5 200 1.60 1.5 6 100 3 2 5 200 1.68 1.7 7 100 3 45 200 1.77 1.9 8 100 3 8 5 200 1.87 1.5

Example 16. PEALD Silicon Oxide Using1-Dimethylamino-1,2,3,4,5,6-Hexamethylcyclotrisilazane in Laminar FlowReactor with 27.1 MHz Plasma

Depositions were performed with1-dimethylamino-1,2,3,4,5,6-hexamethylcycotrisilazane as siliconprecursor and O₂ plasma under conditions as described above in Table 8.Precursor was delivered to chamber with carrier gas Ar flow of 200 sccm.Steps b to e were repeated many times to get a desired thickness ofsilicon oxide for metrology. The film deposition parameters anddeposition GPC are shown in Table 11.

TABLE 11 PEALD Silicon Oxide Film Deposition Parameters and DepositionGPC by 1- dimethylamino-1,2,3,4,5,6-hexamethylcycotrisilazane ReactorOxygen Oxygen Process Dep T Pressure Precursor Plasma Plasma GPCUniformity Condition (° C.) (Torr) flow (s) time (s) Power (W) (Å/cycle)(%) 1 300 3 1 5 200 1.12 4.2 2 300 3 2 5 200 1.30 3.4 3 300 3 4 5 2001.47 2.4 4 300 3 8 5 200 1.62 1.5 5 100 3 1 5 200 1.55 2.3 6 100 3 2 5200 1.72 2.8 7 100 3 8 5 200 1.95 2.0

Example 17. PEALD Silicon Nitride Using1-Dimethylamino-1,2,3,4,5,6-Hexamethylcyclotrisilazane and Ar/N₂ Plasma

A silicon containing film was deposited using1-dimethylamino-1,2,3,4,5,6-hexamethylcyclotrisilazane as the siliconprecursor and Ar/N₂ plasma. The silicon precursor was delivered from acontainer held at 55° C. using 100 sccm Ar carrier gas. The susceptortemperature was set to 300° C., and the reactor was equipped withparallel plate in-situ electrodes. Plasma frequency and power were 13.56MHz and 200 W, respectively. Deposition process steps were carried outas described in Table 12, wherein steps b through e were repeated manytimes to get a desired thickness of silicon oxide for metrology.

TABLE 12 Process for PEALD Silicon Nitride Deposition in the CommercialLateral Flow PEALD Reactor with 1-dimethylamino-1,2,3,4,5,6-hexamethylcyclotrisilazane. Step a Introduce Si wafer to the reactorDeposition temperature = 300° C. b Introduce silicon precursor to thePrecursor pulse = 1 second reactor Carrier gas = 100 sccm Ar; Processgas Argon flow = 500 sccm Reactor pressure = 2 Torr c Purge siliconprecursor with inert Argon flow = 500 sccm gas (argon) Argon flow time =10 seconds Reactor pressure = 2 Torr d Nitridation using Ar/N₂ plasmaArgon flow = 125 sccm Nitrogen flow = 375 sccm Plasma power = 200 WattsPlasma time = 5 seconds Reactor pressure = 2 Torr e Purge Ar/N₂ plasmaPlasma off Argon flow = 500 sccm Argon flow time = 10 seconds Reactorpressure = 2 TorrThe resulting deposited film had a GPC of 0.24 A/cycle with refractiveindex of 1.97.

The foregoing description is intended primarily for purposes ofillustration. Although the invention has been shown and described withrespect to an exemplary embodiment thereof, it should be understood bythose skilled in the art that the foregoing and various other changes,omissions, and additions in the form and detail thereof may be madetherein without departing from the spirit and scope of the invention.

The invention claimed is:
 1. A composition comprising at least onesilicon precursor compound selected from the group consisting of1-silyl-2,2,4,4,6,6-hexamethylcyclotrisilazane,1-(iso-propylaminosilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane,1-(dimethylaminosilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane,1-(iso-propylaminosilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane,1-(methylaminosilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane,1-(dimethylaminomethylsilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane,2-dimethylamino-1,2,3,4,5,6-hexamethylcyclotrisilazane,1-(dimethylamino-methylsilyl)-2,4,6-trimethylcyclotrisilazane,1,2,3-trisilyl-2,2,4,4,6,6-hexamethylcyclotrisilazane,1,2,3-trisilyl-2,4,6-trimethylcyclotrisilazane,2,2,4,4,5,6,6-heptamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane,5-ethyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane,5-n-propyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane,5-iso-propyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane,5-silyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane,5-methylsilyl-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane,5-(dimethylaminosilyl)-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane,5-(dimethylaminomethylsilyl)-2,2,4,4,6,6-hexamethyl-1,3-dioxa-5-aza-2,4,6-trisilacyclohexane.2. The composition of claim 1 further comprising at least one purge gas.